1. Field of the Invention
The present invention relates to a housing for a rotary vane pump having a suction flange and a discharge flange.
2. Description of the Prior Art
Rotary vane pumps are well known. In a rotary vane pump, two rotors synchronously rotate in a housing in opposite directions, without contacting each other. The rotors can have a shape of 8 and are separated from each other and from the stator by a narrow gap. The forwarded gas is transmitted from the suction opening to the discharge opening.
A shaft is driven by a motor. The synchronization of the other shaft is carried out with a tooth gear pair located in the drive space. Lubrication is limited to the drive space separated from the compression chamber by a sealing element.
Because no friction takes place in the compression chamber, the rotary vane pump can be operated with a high speed up to 7,500 revolution/min. The symmetrical mass distribution of the rotors about the shaft axis provides for a perfect dynamic balance, so that the pump operates quietly, despite the large rotational speed.
The rotor shaft bearings are located in two side portions of the housing. The bearing on one side is preferably a fixed bearing, and the bearing on the other side is formed as a floating bearing to provide for non-uniform thermal expansion of the housing and the pistons. Usually, oil is used for lubrication of bearings and the tooth gears. At standard executions, the drive shaft portions that project outwardly, are sealed with sealing oil superimposed, radial shaft seals for shaft protection, the seal ring can rotate on a wearing sleeve that can be replaced.
The object of the invention is to improve state-of-the art rotary vane pumps by a new design of the rotary vane pump housing.